1. Field of the Invention
The present invention relates to a knitted-in slide fastener in which a fastener tape is composed of warp knitting structure and a continuous fastener element row which is of thermoplastic synthetic resin mono-filaments is knitted in and fixed along a fastener element mounting portion of a longitudinal side edge portion of the fastener tape at the same time. More particularly, the invention relates to a knitted-in slide fastener in which the knitting structure of the fastener element mounting portion is formed fine so as to stabilize a pitch between fastener elements and no fraying of composition yarns or separation of fastener element row occurs even when the composition yarn of the fastener element mounting portion is cut out by a sewing needle.
2. Description of the Related Art
For example, Japanese Patent Application Laid-Open No. 8-314 has disclosed a knitted-in slide fastener in which at the same time when a fastener tape is knitted, a continuous fastener element row is knitted in and fixed to a fastener element mounting portion formed along a side edge in the longitudinal direction of the fastener tape. In the knitted-in slide fastener disclosed in this publication, another chain knitting yarn is knitted in duplication in a needle loop group composed of fixing chain knitting yarns for the fastener element row which forms a row of wale near a fastener tape main body, so that a foundation structure in the fastener element mounting portion is formed fine by a chain knitting in which knitting pattern thereof is duplicated. Consequently, it is intended to stabilize the dimension of the fastener element mounting portion and fix the fastener element row firmly.
Japanese Patent Application Laid-Open No. 11-187909, for example, has disclosed technology for stabilizing the mounting of the fastener element row. According to the same publication, all the knitting yarns which compose the aforementioned fastener element mounting portion are provided with a higher heat shrinkage characteristic than that of knitting yarns which compose the fastener tape main body and after knitting, are subjected to heat processing, so that composition yarns of the fastener element mounting portion are allowed to shrink largely than the composition yarns of the fastener tape main body. Consequently, it is intended to form the fastener element mounting portion fine so as to tighten the fastener element row more tightly with the fixing chain knitting yarns thereby securing a high coupling strength.
The knitted-in slide fastener disclosed in the above-mentioned publication restricts an operating end of a slider by mounting an upper stop and a lower stop on both end portions thereof like an ordinary slide fastener. Because each of these upper and lower stops is composed of a small piece made of metallic material or synthetic resin material, mounting portions of the stops are protruded outside when such a slide fastener is sewed to trousers or skirt, so that its appearance is not good. Particularly, in case of the upper stops, which are mounted separately to the right and left, it is difficult to fit the slider to the upper stops, so that the fastener portion between the slider and the upper stops is open during use, thereby producing an inconvenience in appearance.
On the other hand, because the knitted-in slide fastener of the invention is excellent in plasticity in terms of the structure thereof as compared to the slide fastener formed of a woven fabric, it has been often employed in particularly plastic clothes. However, if the aforementioned stops are mounted, the inconvenience becomes remarkable. For the reason, since before, end portions of the fastener element row have been sewed directly to clothes through a sewing needle.
When it is intended to mount the fastener element row directly to clothes by sewing the end portions thereof with the sewing needle, the sewing needle should traverse the end portion of the fastener element row. Then, the sewing needle is pierced into the fixing knitting yarns existing at the fastener element mounting portion of the fastener tape or the other composition yarns existing at the same mounting portion located between respective fastener elements, so that the yarns pierced by the sewing needle is cut out. Consequently, by opening/closing operation or mechanical operation upon washing or the like of the slide fastener, fraying in yarn may occur in the fastener element mounting portion and part of the fastener element row may be separated from the fastener tape. Particularly, in the case that heat treatment such as thermal setting is carried out after manufacturing of a fastener stringer like the knitted-in slide fastener of the invention, the yarns are cut out easily due to interference with said sewing needle because hardness and tension of the yarn itself are heightened. Further particularly, if a yarn having a small-diameter in which plasticity is regarded important is used, the yarn is more highly inclined to be cut out.
Accordingly, the present invention has been achieved to solve the above described problems and a concrete point of the invention is to provide a knitted-in slide fastener in which when end portions of the fastener element row of the fastener stringer are mounted directly to clothes by sewing, no fraying occurs in yarns even if knitting yarn, which composes the fastener element mounting portion of the fastener tape, is cut out due to the interference with a sewing needle so that the fastener element row is not separated from the fastener tape at that portion, thereby ensuring an excellent durability.
Especially, because according to the invention, part of the composition yarns of the fastener element mounting portion is composed of composite fiber yarns formed of the heat shrinkage fiber material and the heat fusion fiber material, when heat treatment is carried out after knitting, the heat shrinkage fiber material of the fastener element mounting portion shrinks largely in the longitudinal direction even if the knitting density is set to ordinary density, so that the fastener element mounting portion is formed fine at a high density. Further, tightening force to the fastener element is increased, so that the fastener element row can be fixed firmly to the fastener tape.
Further, according to the structure described above, if the fastener stringer is heat-treated at a higher temperature than the melting point of the heat fusion fiber material, part or all of the heat fusion fiber material is melted at the same time when the heat shrinkage fiber material shrinks, so that it may be fused with the heat shrinkage fiber material and at the same time, also fused with other composition yarns in the vicinity of the fastener element mounting portion.
By cooling this, the melted portion of the heat fusion fiber material is fused with at least the heat shrinkage fiber material and integrated therewith. Thus, even if the heat shrinkage fiber or other composition yarn happens to be cut out with such a situation that the composition yarn of the fastener element mounting portion interferes with the sewing needle when the end portion of the knitted-in slide fastener of the invention is mounted to clothes, fraying in yarn is blocked by this fusion portion because the cut yarn is fused with other yarn through the aforementioned heat fusion fiber material. Further, no further fraying in yarn occurs and then, separation of the fastener element row is not generated while a knitting pattern is maintained.
Further, when said heat fusion fiber material is melted, it is fused with not only the aforementioned yarn but also a portion in contact with the heat fusion fiber material of the element, at the same time. Thus, the fixing of the fastener elements to the fastener tape not only depends upon sandwiching of the upper and lower leg portions by the fixing knitting yarns from the front and rear sides thereof, but also is fastened and stabilized by integration of the composition yarns and the fastener elements through the heat fusion fiber material.
The fastener element mounting portion is formed continuously with the fastener tape main body. That knitting structure utilizes knitting yarns for connecting the fixing knitting yarns with a knitting pattern and various kinds of in-laid yarns to be inserted through the knitting pattern of the fixing knitting yarn as well as the fixing knitting yarns of the fastener element. The typical knitting pattern structure of the fixing knitting yarn includes the chain knitting, tricot knitting, two needle stitch and the like. These knitting pattern structures are knitted independently or in combination. The various kinds of the in-laid yarns include warp in-laid yarn and weft in-laid yarn. The composition yarns in the fastener element mounting portion of the invention contains the fixing knitting yarns and various kinds of the in-laid yarns. Therefore, said composite fiber yarn in the invention is any one of them but not restricted to any special one.
Furthermore, according to the invention, the above-mentioned composite fiber yarn is the fixing knitting yarn and the fixing knitting yarn is the chain knitting yarn. Because one chain knitting pattern is composed of the knitting yarn of two needle loops, if the chain knitting yarn is employed as the fixing knitting yarn of the fastener element row, two knitting yarns of the needle loop stride over the upper leg portion of the fastener element while a knitting yarn of its sinker loop is disposed below the lower leg portion such that it intersects perpendicularly, so as to sandwich and fix the upper and lower leg portions with respective knitting yarns. Therefore, its tightening force is very strong as compared to the other fixing knitting pattern structure. Employing the chain knitting yarn as the fixing knitting yarn as well as a decreased elongation in the direction of the wale based on the structure of the knitting pattern thereof is preferable for stabilizing the fixing of the fastener element when it is intended to knit the fastener elements into the fastener tape.
This chain knitting structure produces little elongation in a direction of wale as described above, and further, if the chain knitting structure is employed as an element fixing structure, a larger tension than that of an ordinary knitting is generated in the chain knitting yarns after knitting. There is such an inclination for non-shrinkable yarns such as ordinary cotton yarn and synthetic fiber yarn. However, since the heat shrinkage fiber material is used as the chain knitting yarn in the invention, after shrinking, a larger tension is generated so that a strong tension is applied in a slide fastener which is a final product.
When the end portion of the fastener element row of the knitted-in slide fastener is mounted to clothes by sewing with this condition, the yarn, which most often interferes with a sewing needle and is cut out, of the composition yarns in the fastener element mounting portion is often the aforementioned fixing chain knitting yarn which is exposed on a surface of the fastener element under a strong tension.
According to the invention, as described above, the composite fiber yarn formed of the heat shrinkage fiber material and the heat fusion fiber material is employed as the fixing chain knitting yarn and then, by heating this, the heat shrinkage fiber material is allowed to shrink in the direction of the yarn and at the same time, the heat fusion fiber material is fused so that the heat shrinkage fiber is fused and integrated with the composition yarns in the vicinity of the fastener element mounting portion. With this fusing, when it is intended to mount the end portion of the fastener element row directly to any mounted object such as clothes by sewing, even if the sewing needle is pierced into the fixing chain yarn and the yarn is cut out at that portion, no fraying occurs in the yarn because the cut-out chain knitting yarn is fused with the other composition yarns, so that the fastener element row is never separated from the fastener tape.
Further, the feature of the invention is that the warp in-laid yarn which is entangled with the sinker loop of the fixing chain knitting yarn is the composite fiber yarn and the feature of the invention according to claim 4 is that the weft in-laid yarns which are to be inserted between the sinker loop and needle loop of the fixing chain knitting yarn are the composite fiber yarns. In this case, only the warp in-laid yarn or the weft in-laid yarn may be the composite fiber yarn and of course, the fixing chain knitting yarns other than the warp in-laid yarn and weft in-laid yarn or other fixing knitting yarn, or other composition yarn of the fastener element mounting portion may be partly of the composite fiber yarn.
Furthermore, according to the invention, the heat fusion fiber material may be composed of fiber having a core/sheath structure and the sheath thereof is composed of the heat fusion material. Further, the heat fusion fiber material may be composed of fiber yarn having a side-by-side structure and part of the composition fiber material disposed inside and outside thereof is composed of the heat fusion fiber material.
Then, in case of the fiber in the core/sheath structure, the sheath and in case of the fiber in the side-by-side structure, part of the composition fiber material disposed inside and outside thereof is formed of the heat fusion fiber material. Therefore, if this heat fusion fiber material is melted, that heat fusion fiber material is fused between the aforementioned heat shrinkage fiber material and the fixing knitting yarn in the fastener element mounting portion or other composition yarns, so that the same function as the above-described one is exerted.
Further, according to the invention, a yarn structure of the composite fiber yarn composed of the heat shrinkage fiber material and the heat fusion fiber material may be employed. This composite fiber yarn may be of a blended yarn of the heat shrinkage fiber and the heat fusion fiber. However, in this case, the heat fusion fiber is fused with the heat shrinkage fiber when it is melted upon heat treatment. Therefore, it is difficult to expect that not only the yarn itself is hardened, but also it is hardly fused with other composition yarns in the fastener element mounting portion composed of ordinary fiber material and the above-described inconvenience which occurs when it is cut out by the sewing needle is solved.
Therefore, the composite fiber yarn is desired to have such a structure which allows melted heat fusion fiber material to be fused with other yarns around it. Both the heat shrinkage fiber material and the heat fusion fiber material are preferred to be of mono-filament or multi-filament made of thermoplastic resin. Usually, as mentioned by the invention of claim 7, the composite fiber yarn is composed of a twisted yarn having a small number of twists formed of fiber yarn made of the heat shrinkage fiber material and the fiber yarn made of the heat fusion fiber material.
Alternatively, the composite fiber yarn itself employs the core/sheath structure and the core yarn is composed of the heat shrinkage fiber material while the sheath yarn is composed of the heat fusion material. Further, such as the invention according to claim 9, the composite fiber yarn itself employs the side-by-side structure formed of the heat shrinkage fiber material and heat fusion fiber material.
With such a structure, as described above, the density of the fastener element mounting portion is increased so that the configuration thereof is stabilized and the mounting strength of the elements is improved. By fusing the composition yarns of the fastener element mounting portion with each other with the heat fusion fiber material, even if part of the composition yarns in the fastener element mounting portion is cut out by a sewing needle when an end portion of the fastener element row in the slide fastener which is a final product is fixed directly to a mounted object such as clothes by sewing, separation of the fastener element row from the fastener tape is prevented.